Customize blocks on htmlmail body

I want to use my current theme to send HTMLmail, but not all the blocks that on my site are on menu bar, left and right columns. Do you know how remove (or hide) some blocks from e-mail template, or work with a clean template to, taking the theme characteristics add only some blocks (header, foot, disclaimer...).

I'm sure that the answer is so easy and there is not necessary modify code, but I can't find it, and I believe that I'm going by a bad way.